Development and characterization of the readout system for POLARBEAR-2
Abstract
POLARBEAR-2 is a next-generation receiver for precision measurements of the polarization of the cosmic microwave background (Cosmic Microwave Background (CMB)). Scheduled to deploy in early 2015, it will observe alongside the existing POLARBEAR-1 receiver, on a new telescope in the Simons Array on Cerro Toco in the Atacama desert of Chile. For increased sensitivity, it will feature a larger area focal plane, with a total of 7,588 polarization sensitive antenna-coupled Transition Edge Sensor (TES) bolometers, with a design sensitivity of 4.1 uKrt(s). The focal plane will be cooled to 250 milliKelvin, and the bolometers will be read-out with 40x frequency domain multiplexing, with 36 optical bolometers on a single SQUID amplifier, along with 2 dark bolometers and 2 calibration resistors. To increase the multiplexing factor from 8x for POLARBEAR-1 to 40x for POLARBEAR-2 requires additional bandwidth for SQUID readout and well-defined frequency channel spacing. Extending to these higher frequencies requires new components and design for the LC filters which define channel spacing. The LC filters are cold resonant circuits with an inductor and capacitor in series with each bolometer, and stray inductance in the wiring and equivalent series resistance from the capacitors can affect bolometer operation. We present results from characterizing these new readout components. Integration of the readout system is being done first on a small scale, to ensure that the readout system does not affect bolometer sensitivity or stability, and to validate the overall system before expansion into the full receiver. We present the status of readout integration, and the initial results and status of components for the full array.
Keywords
Cite
@article{arxiv.1410.7488,
title = {Development and characterization of the readout system for POLARBEAR-2},
author = {D. Barron and P. A. R. Ade and Y. Akiba and C. Aleman and K. Arnold and M. Atlas and A. Bender and D. Boettger and J. Borrill and S. Chapman and Y. Chinone and A. Cukierman and M. Dobbs and T. Elleflot and J. Errard and G. Fabbian and C. Feng and A. Gilbert and N. Goeckner-Wald and N. W. Halverson and M. Hasegawa and K. Hattori and M. Hazumi and W. L. Holzapfel and Y. Hori and Y. Inoue and G. C. Jaehnig and A. H. Jaffe and N. Katayama and B. Keating and Z. Kermish and R. Keskitalo and T. Kisner and M. Le Jeune and A. T. Lee and E. M. Leitch and E. Linder and F. Matsuda and T. Matsumura and X. Meng and H. Morii and M. J. Myers and M. Navaroli and H. Nishino and T. Okamura and H. Paar and J. Peloton and D. Poletti and C. Raum and G. Rebeiz and C. L. Reichardt and P. L. Richards and C. Ross and K. Rotermund and D. E. Schenck and B. D. Sherwin and I. Shirley and M. Sholl and P. Siritanasak and G. Smecher and N. Stebor and B. Steinbach and R. Stompor and A. Suzuki and J. Suzuki and S. Takada and S. Takakura and T. Tomaru and B. Wilson and A. Yadav and H. Yamaguchi and O. Zahn},
journal= {arXiv preprint arXiv:1410.7488},
year = {2014}
}
Comments
Presented at SPIE Astronomical Telescopes and Instrumentation 2014: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. Published in Proceedings of SPIE Volume 9153